A/6-.l/' 


Hawaii  Agricultural  Experiment  Station, 


HONOLULU. 


J.  G.  SMITH,  Special  Agent  in  Charge. 


UNIV.  OF  FL  LIB 
DOCUMENTS?  Dfl*T 


PRESS  BULLETIN  No.  JO. 


~ORY 


Th  E  PINEAPPLE  SCALE. ] 
(  Diaspis  bromeliae  KernerJ 


By  D.  L.  Van  Dine, 


|25_       MSB:* 
Is*  HOW  — 


Entomologist,    Hawaii    Experiment   Station,    U.    S.    Dep't    of 

Agriculture. 


This  pest  of  the  pineapple  is  a  scale-insect"  which,  because 
of  its  special  fondness  for  this  plant,  has  received  the  common 
name  the  "Pineapple  Scale."  The  insect  was  first  described 
by  Kerner  in  1778,  and  besides  attacking  the  pineapple,  is 
widely  distributed  on  various  plants  in  greenhouses.  It  has 
been  reported  from  the  countries  of  northern  Europe ;  from 
Massachusetts,  Washington,  D.  C,  Ohio,  California,  and  Flo- 
rida in  the  United  States;  and  from  Mexico,  Jamaica,  Cape 
Colony,  and  Natal.  Prof.  V.  L.  Kellogg  of  Stanford  Univer- 
sity, to  whom  the  writer  is  indebted  for  the  determination  of 
the  insect,   says:     "Probably  bromeliae  (pineapple-scale)   will 


Reprint  from  The  Hawaiian  Forester  and  Agriculturist. 
Vol.   I.       No.  5.       May,   1904.       pp.   111-114. 

2For  a  general  discussion  of  scale-insects  see  Press  Bulletin  No.  8 
of  this  Station. 


PL.  I,  THE  PINEAPPLE  SCALE 


be  found  in  time  wherever  the  pineapple  is  grown."  Other 
food  plants  are  ivy,  canna,  hibiscus,  acacia,  olea  (olive),  bill- 
bergia,  and  certain  varieties  of  greenhouse  palms.  The  writer 
took  the  first  specimens  of  this  scale  from  a  pineapple  planta- 
tion at  Wahiawa,  Oahu,  on  October  26,  1903,  and  since  then 
has  observed  the  pest  in  every  plantation  visited  on  this  Island 
and  the  Island  of  Hawaii.  Although  occurring  generally 
throughout  the  Islands,  Mrs.  M.  E.  Fernald  does  not  record  it 
from  Hawaii  in  her  catalogue  of  Coccids/  nor  is  it  found  in 
Mr.  Kirkaldy's  recent  work  on  Hemiptera  in  Fauna  Hawaiiensis. 
Mr.  P.  H.  Rolfs4  says  regarding  the  appearance  of  this  insect 
in  Florida:  "  It  has  been  found  repeatedly  on  plants  imported 
from  Hawaii,  and  has  been  disseminated  to  many  parts  of  Flo- 
rida." Dr.  L.  Reh  of  Hamburg,  Germany,  also  records0  the 
pest  as  common  in  these  Islands,  having  collected  specimens 
himself  at  the  Government  Nursery  on  Feb.  28,  1902. 

Prof.  F.  V.  Theobald,  an  English  authority  on  economic 
entomology,  says:  "  Pineapples  are  frequently  damaged  by  a 
scale  insect,  which  now  and  then  causes  the  fruit  to  rot  *  *  * 
This  scale  is  the  Pineapple  Scale  {Diaspis  bromeliae,  Kerner.) 
The  scale  is  thin,  circular  and  pure  white — the  females  yellow 
or  orange.  Like  most  Diaspids,  they  burrow  beneath  the  epi- 
dermis of  the  plants  and  become  almost  entirely  hidden.  It 
chiefly  attacks  the  leaves,  but  now  and  then  the  fruit.  It 
should  be  destroyed  as  soon  as  the  fruit  is  cut."6 

Dr.  Reh  in  describing  the  work  of  this  scale  states  that  it  at- 
taches itself  to  the  plant  on  the  base  of  the  leaf,  spreading  from 
there  to  the  stem  and  eventually  covering  the  entire  plant, 
which  it  kills.     On  the  fruit  it  attacks  principally    the  green, 


3  A  Catalogue  of  the  Coccidae  of  the  World.  Fernald,  Bui.  88.   Hatch 
Experiment  Station,  1903. 

"Pineapple  Growing.     Rolfs.    Farmers'  Bulletin  No.  140.     U.  S.  De- 
partment of  Agriculture,  1901. 

3Zeitschrift  fuer  Entomologie.     Jan.  15,  1904,  p.  30. 

8First  Report  on  Economic  Zoology.     Theobald.   1903.  British  Muse- 
um, London. 


unripe  portion.  A  symptom  of  an  attack  is  rust  colored  spots 
on  the  leaves.  Dr.  Reh  says  further  that  milk  of  lime  was 
used  as  an  insecticide  for  this  pest  in  Berlin  and  Russia. 

These  small,  scale-like  insects  are  very  conspicuous,  be- 
cause of  their  color,  and  not  easily  mistaken  for  other  forms. 
The  scale  and  not  the  insect  itself  is  the  object  commonly 
seen.  The  insect  is  found  beneath  this  secretion,  which  serves 
as  a  shield.  In  the  case  of  this  insect  the  scale  or  protective 
armor  is  made  up  partly  of  a  waxy  secretion  of  the  insect  and 
partly  of  molted  skins.  The  insect  itself  in  the  adult  stage  is 
quite  well  buried  beneath  the  epidermis  of  the  plant  and  hence 
the  necessity  of  combating  the  pest  in  its  early  stages. 

The  pineapple  scale  can  be  controlled  by  spraying  where  it 
occurs  in  the  field.  The  cheaper  and  easier  method  is  by 
proper  preventive  measures  to  keep  the  pest  from  gaining 
a  foothold  in  the  plantation.  These  measures  are  to  burn  all 
leaves  where  the  pest  is  at  all  evident  after  harvesting  the 
crop,  to  dip  young  plants  in  an  insecticide  before  plant- 
ing and  to  produce  the  maximum  vigor  and  health  of  the 
plants  by  thorough  cultivation  and  fertilization.  In  the  ques- 
tion of  the  control  of  the  insect  pests  and  diseases  of  plants,  no 
one  point  is  more  important  than  vigorous  and  clean  cultiva- 
tion and  the  proper  supply  of  plant  food  and  moisture.  It  is 
an  accepted  fact  in  applied  entomology  that  a  healthy  growing 
plant  is  capable  of  offering  resistance  to  the  attack  of  an  insect 
pest. 

Dr.  L.  O.  Howard,  entomologist  of  the  U.  S.  Department  of 
Agriculture,  mentions7  a  Hymenopterous  parasite,  Aspidiotipha- 
gus  citrinus  Craw.,  bred  from  the  pineapple  scale  at  Washington. 

The  remedies  advised  by  Mr.  Rolfs  in  his  Bulletin  on  Pine- 
apple Growing,  have  been  verified  in  experiments  at  this  Sta- 
tion and  on  our  recommendation  have  been  tried  and  reported 
as  successful  by  the  managers  of  two  pineapple  plantations. 


Insect  Life,  Vol.  VI.,  p.  231 


REMEDIES 

Kerosene  emulsion: 

Whale-oil  soap  (or  any  hard  soap  shaved  fine) J4  pound. 

Water 1  gallon. 

Kerosene  (coal-oil) 2  gallons. 

Dissolve  the  soap  in  the  water  while  it  is  boiling  over  a  fire. 
When  the  soap  is  well  dissolved,  remove  the  solution  a  safe 
distance  from  the  fire  and  add  it  to  the  coal-oil.  Churn  the 
mixture,  using  a  strong  force  pump,  for  a  few  minutes  until  it 
has  a  creamy  consistency.  If  the  emulsion  is  well  made  the 
oil  will  not  rise  to  the  surface  on  standing.  This  is  the  stock 
solution  and  will  keep  for  several  weeks.  When  wanted  for 
use  dilute  one  part  of  the  stock  solution  with  ten  parts  of  water. 
Dip  the  plants  in  the  emulsion  before  setting  out  in  the  field  or 
apply  as  a  spray  to  infested  plants  in  the  field.  When  applied 
as  a  spray  in  the  field  do  not  treat  the  plants  when  the  fruit-bud 
is  forming — do  the  spraying  either  before  the  fruit-bud  starts 
to  grow  or  after  it  is  partly  grown.  Use  only  enough  of  the 
mixture  to  wet  thoroughly  the  scales.  If  too  much  is  used  it 
will  collect  at  the  base  of  the  leaves  or  run  down  about  the 
crown  and  it  is  apt  to  injure  the  plant. 

Resin  wash: 

Resin pounds .  .  5 

Caustic  soda  (crude  78  per  cent.) .  .  1 

Fish  oil  (whale  oil  soap) .  .  i 

Water gallons.  .20 

Full  directions  for  the  preparation  of  resin  wash  are  given  in 
Bulletin  3  of  the  Hawaii  Experiment  Station. 

In  using  the  resin  wash  follow  the  directions  given  for  the 
kerosene  emulsion. 

The  emulsion,  being  a  more  permanent  mixture,  more  easily 
prepared  and  equally  as  efficient,  recommends  its  use  in  place 
of  the  resin  wash;  however,  the  use  of  either  mixture  is  a  point 
for  the  planter  to  determine  to  his  own  satisfaction. 


The  question  of  ingredients  and  proper  spraying  apparatus 
is  a  very  important  one.  Failure  is  in  the  majority  of  cases 
due  to  poor  material  or  insufficient  apparatus.  A  cheap  pump, 
which  soon  becomes  useless,  is  always  more  expensive  than  a 
well-made  outfit  at  whatever  cost.  For  field  spraying  where 
the  ground  is  rocky  and  uneven,  a  compressed-air  knapsack 
sprayer  will  be  found  suitable,  while  on  level  land,  which  will 
permit  a  wagon  passing  through  the  rows,  a  barrel  outfit  will 
be  found  the  more  desirable.  These  are  points  which  only  a 
knowledge  of  local  conditions  will  permit  definite  advic  e 
being  given.  Further  information  will  be  gladly  given.  Ad- 
dress Mr.  Jared  G.  Smith,  Director,  Hawaii  Experiment  Sta- 
tion, Honolulu,  Hawaii. 

Honolulu,  August  11,  1904. 


UNIVERSITY  OF  FLORIDA 


3  1262  08929  1123 


